Darwin's theory of evolution has proven to be extremely useful in explaining the evolution of species and has provided a framework for us to understand life at the species level. With the advances of molecular biology in the past 30 years, we now understand that life on earth is essentially the interplay between the genetic code and the environment. It is now well accepted that whenever there is major environmental change, mass extinction ensues to clear out the unfit species and make way for new species that are better adapted to survive in the new environment. Like all living organisms on earth, we human have also evolved through the ages as a result of evolutionary pressure placed on our genome by environmental factors. Hence, human body as it exists today is the product of the environment; it has been evolved to be optimally suited for a certain set of environmental conditions that has dominated earth for the past few million years.
Given that the human body has been evolved to suit a certain kind environment, it stands to reason that human health is inextricably linked to its surrounding environment. However, our understanding of the environmental effects on health is still very poorly developed. Modern medicine largely ignores the effects of the environment and takes the view that the human body is more like a machine then an integral part of the environment and human diseases are best treated by “fixing” the broken parts. For example, we only see cancer as a cellular dysfunction which manifests as out-of-control cell growth, but we fail to explain why cells grow out of control. All mainstream cancer therapies aim to eradicate these aberrant cells, but we know that cutting out the cancerous cells do not guaranty a cure. On the other hand, we know that there are cancer patients who spontaneously heals without any medical intervention. In many such cases, the patients often attribute the miraculous healing to change in their lifestyles, living conditions, and mental attitudes.
At a conceptual level, spontaneous healing claims are not completely without logics. The phrase “under the weather” suggests that our ancestors have long recognized the important links between the environmental factors and our health. Among the environmental factors, levels of solar radiation, atmospheric temperature, surface temperature, wind, atmospheric pressure, altitude, etc. all have immediate and observable effects on our body and mental states. For example, if the temperature is too high, we will sweat and lose water. If the air is too dry, our skin will crack. These are extreme environmental conditions that can produce an immediate result in our body. But what about less extreme changes in the environment? We know that human body has evolved over millions of years to its current form. The environment has more or less stayed the same for the past few millions of years for us. But in the past hundred years, through industrialization, we have drastically altered our own environment. We have become less active, exposed ourselves to far more sensory stimulations then our ancestors, and fed our bodies foods that were not readily available to our ancestors. Our bodies have not had time to adjust to these sudden environmental changes and we are just beginning to notice their impact on our health. For example, in the U.S., the link between obesity and fast food is now well recognized.
Another important environmental change is global warning. From 1981 to 1990, the temperature of earth has risen 0.48° C. This number may seem insignificant at first, but when we recognize that this change is here to stay, we must ask what impact will this have on our health over the long term.
To answer these questions, tools for collecting data about human health and the environment as well as methods for analyzing the data are needed. More importantly, to maintain human health, devices that can provide input about the body's state of health and the environmental conditions will be very useful.